US3783926A - Tire having two-ply carcass merging into one ply - Google Patents

Tire having two-ply carcass merging into one ply Download PDF

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Publication number
US3783926A
US3783926A US00247780A US3783926DA US3783926A US 3783926 A US3783926 A US 3783926A US 00247780 A US00247780 A US 00247780A US 3783926D A US3783926D A US 3783926DA US 3783926 A US3783926 A US 3783926A
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US
United States
Prior art keywords
cords
tire
carcass
ply
rubber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00247780A
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English (en)
Inventor
Zarauz Y De
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Compagnie Generale des Etablissements Michelin SCA
Original Assignee
Compagnie Generale des Etablissements Michelin SCA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Compagnie Generale des Etablissements Michelin SCA filed Critical Compagnie Generale des Etablissements Michelin SCA
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Publication of US3783926A publication Critical patent/US3783926A/en
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Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D30/00—Producing pneumatic or solid tyres or parts thereof
    • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
    • B29D30/38—Textile inserts, e.g. cord or canvas layers, for tyres; Treatment of inserts prior to building the tyre
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D30/00—Producing pneumatic or solid tyres or parts thereof
    • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
    • B29D30/08—Building tyres
    • B29D30/20—Building tyres by the flat-tyre method, i.e. building on cylindrical drums
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D30/00—Producing pneumatic or solid tyres or parts thereof
    • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
    • B29D30/08—Building tyres
    • B29D30/20—Building tyres by the flat-tyre method, i.e. building on cylindrical drums
    • B29D30/30—Applying the layers; Guiding or stretching the layers during application
    • B29D30/3007—Applying the layers; Guiding or stretching the layers during application by feeding a sheet perpendicular to the drum axis and joining the ends to form an annular element
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
    • B60C9/02—Carcasses
    • B60C9/04—Carcasses the reinforcing cords of each carcass ply arranged in a substantially parallel relationship
    • B60C9/08—Carcasses the reinforcing cords of each carcass ply arranged in a substantially parallel relationship the cords extend transversely from bead to bead, i.e. radial ply
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
    • B60C9/02—Carcasses
    • B60C9/16—Carcasses built-up with metallic reinforcing inlays
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T152/00—Resilient tires and wheels
    • Y10T152/10—Tires, resilient
    • Y10T152/10495—Pneumatic tire or inner tube
    • Y10T152/10855—Characterized by the carcass, carcass material, or physical arrangement of the carcass materials
    • Y10T152/10873—Characterized by the carcass, carcass material, or physical arrangement of the carcass materials with two or more differing cord materials

Definitions

  • a tire carcass is formed of a pair of plies adjacent to each other and extending through the tire from one bead to the other.
  • Each ply comprises cords arranged with the same pitch and along the same direction, and the cords of each ply are staggered with respect to those of the other by half the pitch.
  • the cords of the two plies, in regions of the carcass close to the beads, are located respectively at different distances from the inner wall of the tire.
  • the manufacture of a tire entails initially the building of a cylindrical blank, which may be formed of the carcass only or which may already combine all the structural parts of the tire.
  • the cylindrical blank is shaped and assumes a substantially toroidal shape.
  • the cords of each carcass ply which are parallel and equally spaced in the cylindrical blank, move away from each other, retaining their initial spacing at the height of the bead wires and becoming spaced farther and farther apart as they approach the crown of the carcass.
  • the cords, remaining in the radial planes have their spacing or pitch increased proportionally to their distance from the axis of the tire.
  • the shaping thus has the effect of stretching the bridge of rubber connecting two adjacent cords of one and the same ply.
  • the width of this bridge of rubber which is uniform in the cylindrical blank, is increased considerably in the finished tire between the bead and the shoulder.
  • An elementary calculation shows that, in a radial-carcass tire, the width of the bridge of rubber varies between a minimum s at the height of the bead wires and a maximum a at the height of the crown, such that:
  • d being the diameter of the cords and r the shaping ratio, that is to say, the ratio of the maximum diameter of the carcass, measured at the intersection with the mid-plane of the tire, and the minimum diameter of the carcass, measured at the base of the beads.
  • the maximum width 6, is a multiple of the minimum width 6,, their ratio being, for instance, included between and 30. In certain cases, 6, may assume a rather large value.
  • a cord diameter d of the order of 3 mm a shaping ratio 1' greater than or equal to 2
  • a minimum bridge of rubber e of the order of 0.4 mm
  • a maximum bridge of rubbers of the order of 4 mm, namely ten times larger than s It is undesirable for the rubber bridges between adjacent cords to stretch excessively, as this has the effect of accentuating the heterogeneity of the carcass.
  • a first remedy consists in reducing as 'much as possible the minimum space i between cords so as to limit the maximum space 6,.
  • the minimum space i between cords so as to limit the maximum space 6,.
  • the cords have a pitch, that is to say, a center-to-center distance, which is as small as possible.
  • This method has only limited possibilities. It is obvious that one cannot reduce the pitch and the width of the bridge of rubber beyond a minimum value for each type of cord. In the above numerical example it is difficult to reduce the minimum bridge of rubber between cords of 3 mm diameter beyond 0.4 mm or 0.3 mm. Assuming that one succeeds in reaching 01 mm, the maximum bridge of rubber e, will be reduced only by about 0.2 mm.
  • An object of the invention is to remedy the deficiencies of the prior art noted above.
  • an object of the invention is to reduce the maximum width of the bridges of rubber between adjacent carcass cords without thereby producing a harmful stiffening of the sidewalls, particularly in the regions adjacent to the tread where they are subjected to strong deformations and strong stresses.
  • Another object of the invention is to obtain this result without having to modify in an undesirable way the ordinary tire building operations.
  • a tire having a carcass formed of at least one pair of adjacent plies extending fromone bead to the other and formed of cords arranged with the same pitch and with the same orientation.
  • the tire is characterized in that the cords of the pair of plies are staggered half a pitch from one ply to the next.
  • the cords of the two plies are respectively arranged at different distances from the inner wall of the tire.
  • successive cords of one ply are inserted between adjacent cords of the other ply, and the cords of both plies are substantially at the same distance from the inner wall of the tire.
  • the pitch of the cords of a ply is the distance between adjacent cords measured from center to center.
  • the pitch is equal to the sum of the diameter of one of the cords and the distance between adjacent cords, that is to say, the width of the bridge of rubber.
  • the invention thus comprises two plies of parallel cords arranged in such a manner that each cord of one ply is at an equal distance from two cords of the other ply.
  • the cords of the two plies are superimposed in the sidewalls in the zones adjacent to the beads but are juxtaposed as though they were part of a single ply in the regions of the sidewalls adjacent to the tread and below the tread.
  • the invention is preferably applied to a tire having a radial carcass and/or a carcass reinforced with cords of material of high modulus of elasticity and in particular metal cords.
  • e and e are preferably close to half the diameter of the cords and in any event between one-fourth and three-quarters of the diameter of the cords.
  • the method in accordance with the invention for the manufacture of a tire by forming a cylindrical blank and subsequently shaping it is characterized in that, in order to build the cylindrical blank, there is used at least one ply formed of two super-imposed layers of cords having the same orientation and the same pitch e.
  • the cords of one layer are staggered by half a pitch from those of the other layer, and the pitch e is between 2d and 4d/1 l, d being the diameter of the cords and 'r the shaping ratio of the carcass.
  • the cords are of metal, and a single composite ply is employed, the cords of which are arranged parallel to the axis of the cylindrical blank.
  • the pitch e is close to 3d/2 and is between 5d/4 and 7d/4 for ordinary shaping ratios.
  • the pitch e of the cords of the two layers of the composite ply is selected as a function of the height at which it is desired that these two layers of cords merge in the finished tire.
  • the pitch must be equal to 4d/3 if one desires the spacing between cords of the same layer to be equal to the diameter of the cords d at the midheight of the sidewall, and the merging of the two layers of cables to start at this height.
  • the merging commences at one-third the height of the carcass.
  • a composite ply with two layers of parallel cables staggered from one layer to the other by half a pitch can be obtained by any suitable means.
  • calenders of a type customary for the making of plies.
  • One advantage of the invention is that, because of the use of composite plies, it makes it possible to manufacture tires of very large dimensions which can withstand very high loads. With the technique of the single-ply radial carcass, it is necessary in order to pass from one size tire to a larger size to use thicker cords, which gives rise to larger and larger bridges of rubber in the sensitive zones.
  • a radial carcass with a composite ply in accordance with the invention although formed of cords of smaller diameter, can present a greater resistance per centimeter and smaller bridges of rubber than a carcass of the same size formed of a ply with a single layer of cords.
  • FIG. 1 is a view in radial section of a tire in accordance with the invention
  • FIG. 2 is a fragmentary view in side elevation of the carcass of the tire of FIG. 1;
  • FIGS. 3, 4, 5 and 6 are sectional views on a larger scale of the tire of FIG. 1 along the lines 33, 4-4, 5-5, and 66 of FIG. 1;
  • FIG. 7 is a sectional view on the same scale as FIGS. 3 to 6 of a composite ply used to construct the carcass of the tire shown in FIGS. 1 to 6;
  • FIG. 8 is an elevational view, on a reduced scale, showing the composite play of FIG. 7 on a cylinder.
  • FIG. 1 shows a tire 10 in accordance with the invention.
  • the carcass is distinguished in that it comprises two plies of cords 1 I and 12 arranged in radial planes of the tire, as shown in FIG. 2.
  • the carcass is anchored at its ends around two bead wires 13 located in the beads 14. It extends into the sidewalls 15 and below the tread reinforcement 17 composed of five superimposed plies of metal cords which stiffen the tread 18.
  • FIG. 1 illustrates the definition of the shaping ratio of the carcass, this ratio being equal to Rs/Rp.
  • the cords of the ply I I and those of the ply 12 are substantially at the same distance from the inner wall 20 of the tire in the region of the carcass which is remote from the bead wires 13 (FIGS. 5 and 6) and are at definitely different distances therefrom in the vicinity of the bead wires 13 (FIGS. 3 and 4).
  • each cord of the ply 11 is equidistant from the two closest cords located in the ply 12.
  • FIG. 7 there is shown in section the composite ply with two layers of cords l1 and 12 as it is before positioning and as it is in the tire at the height of the bead wires 13.
  • the composite ply with two layers of cords l1 and 12 as it is before positioning and as it is in the tire at the height of the bead wires 13.
  • it comprises three layers of rubber 24, 25, 26, the intermediate layer being thinner than the other two.
  • FIGS. 3 to 7 there have been indicated the values of the pitch e and of the rubber bridges e at the different heights, for the case of a shaping ratio of 2.
  • FIG. 8 shows how one can obtain a composite ply with two layers of cords 11 and 12 with pitch e in each layer, staggered half a pitch e/2 from one layer to the other.
  • a cylinder which can be rotated around its axis by a drive system known per se and not shown in the drawing.
  • a lead screw 31 on which a positioning pulley 32 slides.
  • the pulley 32 can move at a speed which is strictly proportional to the speed of rotation of the cylinder 30.
  • a cord 33 corresponding to the cord 11 of FIGS. 1 to 7 has been positioned as a helix around the cylinder 30 which was previously covered with a thin layer of rubber 34 over substantially the entire length of the cylinder. After the positioning and rolling of a very thin separating gum layer 35 in order to cause it to penetrate properly between the turns of the cord 33, the pulley 32 positions a second cord 36 corresponding to the cord 12 of FIGS.
  • the radial tire with composite ply No. 1 has a carcass which has the same strength per cm as the conventional radial-carcass tire. However, it uses cords which are definitely smaller and which are connected at the shoulder by rubber bridges which are three times smaller.
  • the radial tire with composite ply No. 2 employs the same cord as the conventional radial-carcass tire.
  • the strength of the carcass is increased by more than 50 percent, while the rubber bridges in the vicinity of the tread have a width which is more than one-half less.
  • a composite ply can be formed with two layers of cords which differ from one layer to the other but which are arranged with the same pitch and staggered by half a pitch from one layer to the other. Accordingly, the invention is to be construed as including all the embodiments thereof that are within the scope of the appended claims' I claim:
  • a tire comprising an annular tread portion, a pair of sidewalls respectively extending radially inwardly from opposite edges of the tread portion, a pair of shoulders respectively at the junctions of the tread portion and the sidewalls, a pair of beads respectively at the radially inner edges of the sidewalls, and a carcass formed-of at least one pair of plies adjacent to each other and extending through the tire from one bead to the other, each ply comprising cords arranged with the same pitch and along the same direction, the cords of each ply being staggered with respect to those of the other by half the pitch, the cords of the two plies, in regions of the carcass close to the beads, being located respectively at different distances from the inner wall of the tire, and successive cords of each ply, in regions of the carcass between the midheights of the two sidewalls, being inserted between adjacent cords of the other ply, so that the cords of the two plies, in said regions of the carcass between the midheights of
  • a tire according to claim 1 comprising rubber, which forms bridges between the cords, the width of the rubber bridges between adjacent cords at the shoulders being substantially equal to the width of the rubber bridges between adjacent cords of either ply in the beads.
  • a tire according to claim 1 comprising rubber, which forms bridges between the cords, the width of the rubber bridges between adjacent cords at the shoulders being between one-fourth and three-fourths the diameter of the cords.
  • a tire according to claim 1 comprising rubber, which forms bridges between the cords, characterized in that, at all points of the carcass, the width of the rubber bridges between adjacent cords which are at the same distance from the inner wall of the tire is within the range of a value which is a fraction of a cord diameter to a value which slightly exceeds a cord diameter.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Textile Engineering (AREA)
  • Tires In General (AREA)
  • Tyre Moulding (AREA)
US00247780A 1971-04-28 1972-04-26 Tire having two-ply carcass merging into one ply Expired - Lifetime US3783926A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7115304A FR2134244B1 (zh) 1971-04-28 1971-04-28

Publications (1)

Publication Number Publication Date
US3783926A true US3783926A (en) 1974-01-08

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Application Number Title Priority Date Filing Date
US00247780A Expired - Lifetime US3783926A (en) 1971-04-28 1972-04-26 Tire having two-ply carcass merging into one ply

Country Status (11)

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US (1) US3783926A (zh)
JP (1) JPS5131642B1 (zh)
BE (1) BE781955A (zh)
CA (1) CA960122A (zh)
DE (1) DE2220759A1 (zh)
ES (1) ES402217A1 (zh)
FR (1) FR2134244B1 (zh)
GB (1) GB1393713A (zh)
IT (1) IT959116B (zh)
LU (1) LU65254A1 (zh)
NL (1) NL148549B (zh)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4890659A (en) * 1987-04-28 1990-01-02 Bridgestone Corporation Reinforcing laminate for tire and heavy duty pneumatic radial tire using the same
US5616198A (en) * 1994-02-09 1997-04-01 Sumitomo Rubber Industries, Ltd. Pneumatic tire with carcass ply increased in thickness partially in at least the tire shoulder portions
EP1275526A2 (en) * 2001-07-10 2003-01-15 Sumitomo Rubber Industries Ltd. Pneumatic tire
US20060137803A1 (en) * 2002-10-01 2006-06-29 Bridgestone Corporation Method and apparatus for forming cord reinforcement layer for tire
US20070122605A1 (en) * 2005-11-30 2007-05-31 Downing Daniel R Apparatus and method of manufacturing reduced gauge tire ply
US20100147128A1 (en) * 2008-12-16 2010-06-17 Richard David Vargo Method and apparatus for shearing reinforced fabrics
US20160159167A1 (en) * 2013-08-21 2016-06-09 The Yokohama Rubber Co., Ltd. Pneumatic Tire, And Method of Manufacturing Pneumatic Tire

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3303595A1 (de) * 1982-02-11 1983-08-25 Janus GmbH, 4000 Düsseldorf Guertel- oder radialreifen und verfahren und vorrichtung zu dessen herstellung
JP2538858B2 (ja) * 1984-06-26 1996-10-02 株式会社ブリヂストン 新都市交通システム専用軌道車両用空気入りラジアルタイヤ
GB8726625D0 (en) * 1987-11-13 1987-12-16 Holroyd Associates Ltd Flexible reinforced polymeric material

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3500888A (en) * 1965-07-28 1970-03-17 Gen Etablissements Michelin Ra Pneumatic tires and manufacture of the same

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3500888A (en) * 1965-07-28 1970-03-17 Gen Etablissements Michelin Ra Pneumatic tires and manufacture of the same

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4890659A (en) * 1987-04-28 1990-01-02 Bridgestone Corporation Reinforcing laminate for tire and heavy duty pneumatic radial tire using the same
US5616198A (en) * 1994-02-09 1997-04-01 Sumitomo Rubber Industries, Ltd. Pneumatic tire with carcass ply increased in thickness partially in at least the tire shoulder portions
EP1275526A2 (en) * 2001-07-10 2003-01-15 Sumitomo Rubber Industries Ltd. Pneumatic tire
US20030024623A1 (en) * 2001-07-10 2003-02-06 Shinichi Miyazaki Pneumatic tire
EP1275526A3 (en) * 2001-07-10 2003-05-14 Sumitomo Rubber Industries Ltd. Pneumatic tire
US6935395B2 (en) 2001-07-10 2005-08-30 Sumitomo Rubber Industries, Ltd. Pneumatic tire with carcass ply including main cords and auxiliary cords
US20060137803A1 (en) * 2002-10-01 2006-06-29 Bridgestone Corporation Method and apparatus for forming cord reinforcement layer for tire
US20070122605A1 (en) * 2005-11-30 2007-05-31 Downing Daniel R Apparatus and method of manufacturing reduced gauge tire ply
US20100147128A1 (en) * 2008-12-16 2010-06-17 Richard David Vargo Method and apparatus for shearing reinforced fabrics
EP2199040A3 (en) * 2008-12-16 2010-10-13 The Goodyear Tire & Rubber Company Cutter apparatus and method for shearing reinforced fabrics
US20160159167A1 (en) * 2013-08-21 2016-06-09 The Yokohama Rubber Co., Ltd. Pneumatic Tire, And Method of Manufacturing Pneumatic Tire
US10603965B2 (en) * 2013-08-21 2020-03-31 The Yokohama Rubber Co., Ltd. Pneumatic tire, and method of manufacturing pneumatic tire

Also Published As

Publication number Publication date
AU4169272A (en) 1973-12-20
FR2134244B1 (zh) 1973-12-28
ES402217A1 (es) 1975-03-16
CA960122A (en) 1974-12-31
DE2220759A1 (de) 1972-11-16
FR2134244A1 (zh) 1972-12-08
NL7205329A (zh) 1972-10-31
JPS5131642B1 (zh) 1976-09-08
BE781955A (fr) 1972-10-12
IT959116B (it) 1973-11-10
LU65254A1 (zh) 1972-12-11
NL148549B (nl) 1976-02-16
GB1393713A (en) 1975-05-14

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